1. Field
The present disclosure relates generally to electrosurgery and electrosurgical systems and apparatuses, and more particularly, to an electrosurgical apparatus with a multi-button handpiece.
2. Description of the Related Art
High frequency electrical energy has been widely used in surgery. Tissue is cut and bodily fluids are coagulated using electrosurgical energy generated by an electrosurgical unit (ESU), e.g., an electrosurgical generator, and delivered or applied to the tissue by an electrosurgical instrument, e.g., a handpiece.
Electrosurgical instruments generally comprise “monopolar” devices or “bipolar” devices. Monopolar devices comprise an active electrode on the electrosurgical instrument with a return electrode attached to the patient. In monopolar electrosurgery, the electrosurgical energy flows through the active electrode on the instrument through the patient's body to the return electrode. Such monopolar devices are effective in surgical procedures where cutting and coagulation of tissue are required and where stray electrical currents do not pose a substantial risk to the patient.
Bipolar devices comprise an active electrode and a return electrode on the surgical instrument. In a bipolar electrosurgical device, electrosurgical energy flows through the active electrode to the tissue of a patient through a short distance through the tissue to the return electrode. The electrosurgical effects are substantially localized to a small area of tissue that is disposed between the two electrodes on the surgical instrument. Bipolar electrosurgical devices have been found to be useful with surgical procedures where stray electrical currents may pose a hazard to the patient or where other procedural concerns require close proximity of the active and return electrodes. Surgical operations involving bipolar electrosurgery often require methods and procedures that differ substantially from the methods and procedures involving monopolar electrosurgery.
Gas plasma is an ionized gas capable of conducting electrical energy. Plasmas are used in surgical devices to conduct electrosurgical energy to a patient. The plasma conducts the energy by providing a pathway of relatively low electrical resistance. The electrosurgical energy will follow through the plasma to cut, coagulate, desiccate, or fulgurate blood or tissue of the patient. There is no physical contact required between an electrode and the tissue treated.
Electrosurgical systems that do not incorporate a source of regulated gas can ionize the ambient air between the active electrode and the patient. The plasma that is thereby created will conduct the electrosurgical energy to the patient, although the plasma arc will typically appear more spatially dispersed compared with systems that have a regulated flow of ionizable gas.
Atmospheric pressure discharge cold plasma applicators have found use in a variety of applications including surface sterilization, hemostasis, and ablation of tumors. In the latter example, the process can be relatively slow, generate large volumes of noxious smoke with vaporized and charred tissue, and may cause collateral damage to surrounding healthy tissue when high power electrosurgical energy is used. Precision accuracy can also be a problem, due to the width of the plasma beam.
The power of any electrosurgical unit (ESU) or RF-unit (radio frequency unit) is delivered to the patient tissue by an activation command, given by the surgeon. The command interface is usually switches (e.g., buttons), located in the activation accessories of the ESU, e.g., handles (hand-pieces), footswitches and other special instruments. A conventional handle accessory 10 is illustrated in FIG. 1 and includes a housing 2, an electrode 8 and two buttons—one for CUT mode (button 14) and one for COAG mode (button 16). Typically, the buttons 14, 16 are colored by the requirements of specific standards, e.g., yellow for CUT mode, and blue for COAG mode. The 2-button handle 10 uses 3 wires to connect to the ESU 11 via connector 12 and cable 13.
During the course of an electrosurgical procedure, the power setting of each mode may need to be changed several times to adapt to varying operative conditions. Conventionally, this is done by making adjustments on the control panel of the electrosurgical generator unit, and would either need the assistance of a nurse, or require the surgeon to leave the sterile field of the surgical site. It would be advantageous for the surgeon to be able to adjust the electrosurgical power on an as-needed basis by adding additional controls to the electrosurgical hand piece itself. However, additional buttons would require more control wires from the handpiece 10 to the ESU 11; for example, a handle with 3 buttons would require 4 control wires, a handle with 4 buttons would require 5 control wires, i.e., the number of required control wires=the number of buttons+1.
Consequentially, more control wires in the cable 13 between the handpiece 10 and the ESU 11 has at least two disadvantages. First, additional control wires increases the complexity, and hence costs, of the connectors for the handpiece and for the front panel of the ESU. Increased cost is a critical issue in the case of disposable accessories. Secondly, more wires in the cable usually represents more stray capacitance to earth, hence higher leakage currents will be produced. Higher leakage currents are to be avoided when working with higher frequencies, e.g., up to 4 MHz.
Therefore, a need exists for a multi-button handpiece or accessory for controlling an electrosurgical unit or generator that employs a minimum number of control wires.